import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'dart:typed_data';
import 'package:flutter/material.dart';import 'package:social_content_creator/routes/app_routes.dart';
import 'package:social_content_creator/services/image_editing_service.dart'; // Contrat
import 'package:social_content_creator/services/stable_diffusion_service.dart'; // Moteur 1
import 'package:social_content_creator/services/gemini_service.dart';           // Moteur 2
import 'package:image/image.dart' as img;

// Énumération pour le choix du moteur d'IA
enum ImageEngine { stableDiffusion, gemini }

class AiEnhancementScreen extends StatefulWidget {
  final File image;
  final String prompt;

  const AiEnhancementScreen({
    super.key,
    required this.image,
    required this.prompt,
  });

  @override
  State<AiEnhancementScreen> createState() => _AiEnhancementScreenState();
}

enum GenerationState { idle, generating, done, error }

class _AiEnhancementScreenState extends State<AiEnhancementScreen> {
  GenerationState _generationState = GenerationState.idle;
  final List<Uint8List> _generatedImagesData = [];
  StreamSubscription? _imageStreamSubscription;

  // --- NOUVEAUX ÉLÉMENTS ---
  // 1. Instancier les deux services dans une map
  final Map<ImageEngine, ImageEditingService> _services = {
    ImageEngine.stableDiffusion: StableDiffusionService(),
    ImageEngine.gemini: GeminiService(),
  };

  // 2. Garder en mémoire le moteur sélectionné (Stable Diffusion par défaut)
  ImageEngine _selectedEngine = ImageEngine.stableDiffusion;
  // --- FIN DES NOUVEAUX ÉLÉMENTS ---

  Future<void> _generateImageVariations() async {
    if (_generationState == GenerationState.generating) return;

    setState(() {
      _generatedImagesData.clear();
      _generationState = GenerationState.generating;
    });

    try {
      // Préparation de l'image (logique inchangée)
      final imageBytes = await widget.image.readAsBytes();
      final originalImage = img.decodeImage(imageBytes);
      if (originalImage == null) throw Exception("Impossible de décoder l'image.");

      final resizedImage = img.copyResize(originalImage, width: 1024);
      final resizedImageBytes = img.encodeJpg(resizedImage, quality: 90);
      final imageBase64 = base64Encode(resizedImageBytes);

      await _imageStreamSubscription?.cancel();

      // --- UTILISATION DU SERVICE SÉLECTIONNÉ ---
      // On récupère le bon service (Stable Diffusion ou Gemini) depuis la map
      final activeService = _services[_selectedEngine]!;

      _imageStreamSubscription = activeService.editImage(
        imageBase64,
        widget.prompt,
        resizedImage.width,
        resizedImage.height,
        // On demande 3 images à Stable Diffusion, Gemini gèrera ce paramètre
        numberOfImages: _selectedEngine == ImageEngine.stableDiffusion ? 3 : 1,
      ).listen(
            (receivedBase64Image) {
          setState(() => _generatedImagesData.add(base64Decode(receivedBase64Image)));
        },
        onError: (error) {
          if (!mounted) return;
          setState(() => _generationState = GenerationState.error);
          ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text("Erreur de génération : $error")));
        },
        onDone: () {
          if (!mounted) return;
          setState(() => _generationState = GenerationState.done);
        },
      );

    } catch (e) {
      if (!mounted) return;
      setState(() => _generationState = GenerationState.error);
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text("Erreur : ${e.toString()}")));
    }
  }

  void _navigateToPreview(int index) {
    if (index >= _generatedImagesData.length) return;
    final selectedImageData = _generatedImagesData[index];
    final imageBase64 = base64Encode(selectedImageData);
    Navigator.pushNamed(context, AppRoutes.imagePreview, arguments: imageBase64);
  }

  @override
  void dispose() {
    _imageStreamSubscription?.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    const double bottomButtonHeight = 90.0;

    return Scaffold(
      appBar: AppBar(title: const Text("3. Choisir une variation")),
      body: Stack(
        children: [
          SingleChildScrollView(
            padding: const EdgeInsets.fromLTRB(16.0, 16.0, 16.0, bottomButtonHeight),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text("Image Originale", style: Theme.of(context).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold)),
                const SizedBox(height: 8),
                SizedBox(
                  height: 300,
                  width: double.infinity,
                  child: ClipRRect(
                    borderRadius: BorderRadius.circular(12.0),
                    child: Image.file(widget.image, fit: BoxFit.cover),
                  ),
                ),
                const SizedBox(height: 16),

                // --- AJOUT DU SÉLECTEUR DE MOTEUR D'IA ---
                Container(
                  padding: const EdgeInsets.all(12),
                  decoration: BoxDecoration(
                      color: Theme.of(context).colorScheme.primary.withOpacity(0.05),
                      borderRadius: BorderRadius.circular(12),
                      border: Border.all(color: Theme.of(context).colorScheme.primary.withOpacity(0.2))
                  ),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.stretch,
                    children: [
                      Text(
                        "Moteur d'IA pour la variation",
                        style: Theme.of(context).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.bold),
                        textAlign: TextAlign.center,
                      ),
                      const SizedBox(height: 12),
                      SegmentedButton<ImageEngine>(
                        showSelectedIcon: false,
                        segments: const <ButtonSegment<ImageEngine>>[
                          ButtonSegment<ImageEngine>(
                            value: ImageEngine.stableDiffusion,
                            label: Text('Stable Diffusion'),
                            icon: Icon(Icons.auto_awesome_outlined),
                          ),
                          ButtonSegment<ImageEngine>(
                            value: ImageEngine.gemini,
                            label: Text('Gemini'),
                            icon: Icon(Icons.bubble_chart_outlined),
                          ),
                        ],
                        selected: {_selectedEngine},
                        onSelectionChanged: (Set<ImageEngine> newSelection) {
                          // On ne change de moteur que si la génération n'est pas en cours
                          if (_generationState != GenerationState.generating) {
                            setState(() {
                              _selectedEngine = newSelection.first;
                            });
                          }
                        },
                      ),
                      const SizedBox(height: 16),
                      // On garde le prompt de guidage dans le même encart
                      ExpansionTile(
                        title: const Text("Voir le prompt de guidage"),
                        initiallyExpanded: false,
                        tilePadding: EdgeInsets.zero,
                        childrenPadding: const EdgeInsets.only(top: 8),
                        children: [
                          Text(widget.prompt, style: const TextStyle(fontStyle: FontStyle.italic)),
                        ],
                      ),
                    ],
                  ),
                ),
                // --- FIN DE L'AJOUT ---

                const SizedBox(height: 24),
                Text("Variations (cliquez pour choisir)", style: Theme.of(context).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold)),
                const SizedBox(height: 16),
                _buildGeneratedVariationsGrid(),
              ],
            ),
          ),
          Positioned(
            bottom: 0,
            left: 0,
            right: 0,
            child: Container(
              color: Theme.of(context).scaffoldBackgroundColor,
              padding: const EdgeInsets.all(16.0),
              child: FilledButton.icon(
                icon: _generationState == GenerationState.generating ? const SizedBox.shrink() : const Icon(Icons.auto_awesome),
                label: Text(_generationState == GenerationState.generating ? 'Génération en cours...' : 'Générer à nouveau'),
                onPressed: _generationState == GenerationState.generating ? null : _generateImageVariations,
                style: FilledButton.styleFrom(padding: const EdgeInsets.symmetric(vertical: 16)),
              ),
            ),
          ),
        ],
      ),
    );
  }

  // Le reste du fichier est inchangé (_buildGeneratedVariationsGrid)
  Widget _buildGeneratedVariationsGrid() {
    // Si la génération est terminée et qu'il n'y a aucune image (cas d'erreur silencieuse)
    if (_generationState == GenerationState.done && _generatedImagesData.isEmpty) {
      return Container(
        height: 100,
        decoration: BoxDecoration(color: Colors.red.shade50, borderRadius: BorderRadius.circular(8), border: Border.all(color: Colors.red.shade200)),
        child: const Center(child: Text("La génération n'a produit aucune image.", textAlign: TextAlign.center)),
      );
    }

    if (_generationState == GenerationState.idle) {
      return Container(
        height: 100,
        decoration: BoxDecoration(color: Colors.grey.shade200, borderRadius: BorderRadius.circular(8), border: Border.all(color: Colors.grey.shade400, style: BorderStyle.solid)),
        child: const Center(child: Text("Cliquez sur 'Générer' pour commencer.")),
      );
    }

    // On affiche 3 slots, même si Gemini n'en remplit qu'un
    int displayCount = 3;
    if (_selectedEngine == ImageEngine.gemini && _generationState != GenerationState.generating) {
      displayCount = _generatedImagesData.length > 0 ? _generatedImagesData.length : 1;
    }

    return Row(
      mainAxisAlignment: MainAxisAlignment.start,
      children: List.generate(displayCount, (index) {
        bool hasImage = index < _generatedImagesData.length;
        return Expanded(
          child: Padding(
            padding: const EdgeInsets.symmetric(horizontal: 4.0),
            child: AspectRatio(
              aspectRatio: 1.0,
              child: GestureDetector(
                onTap: hasImage ? () => _navigateToPreview(index) : null,
                child: hasImage
                    ? ClipRRect(borderRadius: BorderRadius.circular(8), child: Image.memory(_generatedImagesData[index], fit: BoxFit.cover))
                    : Container(
                  decoration: BoxDecoration(color: Colors.grey.shade300, borderRadius: BorderRadius.circular(8)),
                  child: _generationState == GenerationState.generating ? const Center(child: CircularProgressIndicator()) : const SizedBox(),
                ),
              ),
            ),
          ),
        );
      }),
    );
  }
}